Dental implant system and method of use

ABSTRACT

A dental implant system includes an implant having a well and an abutment having a post shaped to be received in the tapered well. Both the implant and the abutment are made from a millable ceramic, and the abutment post and/or the implant well have grooves carved therein. In one embodiment, the implant and the abutment are joined one to the other with a retentive elastomeric product containing micro-bubbles and micro-spacers. The dental implant system may be produced using a computer-readable medium containing instructions for analyzing surface data and X-ray data, for developing contour data of the implant and of the abutment according to the anatomy of the patient, and for generating machine instruction for milling the implant and the abutment from blocks of the millable ceramic. The invention provides the dentist with total flexibility in determining the most appropriate contours of the implant system and in reducing inventory.

FIELD OF THE INVENTION

The present invention concerns a dental implant system made from amillable ceramic material and related methods of use. More particularly,the present invention concerns a dental implant system, in which animplant having a well engages an abutment having a post and a collarthat extends outwardly to be flush with the outer surface of theimplant. In one embodiment, the implant and the abutment are joined oneto the other with a retentive elastomeric product, which containsmicro-bubbles and spacer elements and which fills grooves provided onthe abutment post and/or the implant well.

BACKGROUND OF THE INVENTION

A dental implant system is an artificial tooth root replacement, whichis used in prosthetic dentistry to support restorations that resemble atooth or a group of teeth. An implant system typically includes animplant or base, which is surgically placed in the jaw of a patient, andan abutment or extension, which extends from the implant to support arestoration.

Known implant systems are essentially of two types. Referring to FIG. 1,a first type of implant system 2 in the prior art includes an implant 4,which is placed in a hole bored in the recipient bone, and an abutment8, which operates as a support for a dental restoration and which mayinclude a metallic interface 6 extending downward to engage implant 4.Implant system 2 also includes a screw-type device 10 engaging abutment8, abutment interface 6 and implant 4 longitudinally.

A second type of implant system 10 is illustrated in FIG. 2 and includesan implant 12, which is placed in a hole bored in the recipient bone andwhich has a sloping shoulder 14. Implant system 10 further includes anabutment 13, which supports restoration 16 (shown in the form of a fronttooth) and which has a locking taper 18 that is force-fitted into a wellin the inner portion of implant 12.

Implants in the prior art (such as those depicted in FIGS. 1 and 2) aregenerally made from titanium due to the strength and biocompatibilityproperties of this metal. In addition, titanium can be successfullyfused into the surrounding bone when osteoblasts move on and into itssurface. This process is generally termed “integration” or“osseointegration” and produces a strong anchoring that prevents anindependent movement of the implant.

Unfortunately, metal implants also have a number of drawbacks, whichinclude:

1. Metal implants are mostly made not from pure titanium, but fromtitanium alloys to improve ease of machining. For example, Grade 5titanium is sometime employed, which is an alloy that contains aluminumand vanadium. Some of those titanium alloys contain elements that arepotentially toxic elements.

2. Metal implants may cause “oral galvanism,” which is a toxic effectcaused by a galvanic current generated from the transport of metal ionsthrough the saliva from the implant to another metallic restoration suchas a different implant, a filling, a crown or an orthodontic device. Asa consequence, the rate of corrosion (or dissolution) of a metal-basedrestoration is increased, leading to dispersion of metal ions andrelated oxides in the patient's body and to sensitivity, inflammations,allergies and autoimmune diseases.

3. The attachment of the internal screw (for example, screw 10 ofFIG. 1) may fail. The screw may loosen, break, and become a source ofbacteria due to manufacturing tolerances between the screw and theimplant, leading to a rejection or to a supporting bone failure for theentire implant.

4. Current implant designs include a number of curvatures and recessesthat may house bacterial colonies and cause infections and inflammationsfor lack of access and proper dental hygiene.

5. Metal implants are rigid attachments that are unsuitable for bridgingto a natural tooth, which by its nature is slightly mobile. Therefore,there is an inherent incompatibility between a metal implant and aneighboring natural tooth. In some instances, a restoration (forexample, an artificial crown) may break due to the inflexibility in theimplant.

6. Metal implants are dark in color and tend to show through gum tissue,making them cosmetically unsightly.

7. Metal implants are manufactured and sold in many sizes and therestoring dentist must carry a significant inventory, leading to asizable monetary investment in implants, abutments, accessories,instruments, etc.

8. The dentist's choice of implant and abutment designs is limited towhat is commercially available, limiting the usefulness of the implantand the creativity of the restoring dentist.

In order to decrease rigidity, metal implants have been proposed thatinclude a plastic element providing the abutment with some degree ofmovement in relation to the implant. Such a plastic element not onlyadds to the complexity of the implant, but unfortunately tends to failafter a few months of service.

Recent research in dental implantology has focused on the use of zircondioxide (ZrO₂, generally identified in the dental field as zirconia) forthe manufacture of dental implants. Zirconia is a high-strength ceramicmaterial that can be milled to shape in a dentist's office usingespecially designed CAD-CAM machines. In addition, zirconia is highlybiocompatible and is more cosmetically pleasing due to its bright,tooth-like color.

The designs of zirconia implants and abutments that have been proposedto date are essentially based on existing metal implant designs. Inparticular, no implant and abutment designs have been proposed thatmaximize the properties of zirconia and that resolve or at leastminimize the drawbacks associated with current metal implant systems.

Therefore, it would be desirable to provide a dental implant system thatis made entirely from zirconia and that maximizes the properties ofzirconia.

It would also be desirable to have a dental implant system that is madewith a reduced number of components than implant systems of the priorart.

It would further be desirable to have a dental implant system that canbe custom-milled to shape in a dental office or at an outside dentallab.

It would further be desirable to have a dental implant system havingcontours that minimize the risk of bacterial infections and that areadaptable for use in different positions within the mouth of thepatient, for example, in the front area of the mouth.

It would further be desirable to have a dental implant system thatallows some degree of movement to the supported restoration in a mannersimilar to natural teeth.

SUMMARY OF THE INVENTION

In its most basic configuration, a dental implant system according tothe present invention includes an implant and abutment each made from amillable ceramic, such as zirconia either in pure form or in the form ofa composition.

The implant is defined by a cylindrical outer surface and by an innersurface shaped to form a well, which are connected one to the other byan annular upper surface.

The abutment includes a lower post shaped to engage the well of theimplant and an upper stump designed to carrying a dental restoration. Acollar is also provided at the transition area between the stump and thepost and, in one embodiment, has a lower outer perimeter substantiallyequal to the outer perimeter of the upper surface of the implant, and anupper outer perimeter substantially equal to the outer perimeter of themargin of the restoration. The collar and the upper surface of theimplant may be flat or contoured to fit the specific anatomy of apatient and are assembled in facing relationship.

In one embodiment of the invention, the post of the abutment includesone or more grooves that extend laterally in relation to thelongitudinal axis of the post, for example, the one or more grooves maybe perpendicular to or extend spirally around the post. The one or moregrooves form annular cavities to be filled by a retentive product (whichin one embodiment may be a retentive elastomeric product) that creates amechanical lock between the abutment and the well, such to counteracttensile and compressive forces applied to the abutment. A “retentiveelastomeric product,” “retentive elastomer,” or “retentive resilientproduct” is defined herein as a polymeric product, which has theproperty of elasticity and/or resiliency and which may be of anychemistry providing such property. This product may or may not havechemical or chemical-physical adhesive properties.

The well may also include one or more recesses, which may or may not bedisposed in facing relationship with at least one of the grooves definedin the post, so to jointly create one or more toroidal cavities.

In one embodiment, one or more longitudinal grooves are carved in thepost of the abutment. Such longitudinal grooves may be arrangedsymmetrically in relation to the longitudinal axis of the post. Inaddition, one or more longitudinal recesses may be carved in the well.The longitudinal grooves and recesses become also filled with theretentive product. Moreover, the longitudinal recesses may be used bythe dentist as guides to place the implant in the alveolar bone bymating the recesses with protrusions on a tool used to insert theimplant into the bone.

When the retentive product has elastomeric properties, it may includemicro-bubbles that provide the desired elastic properties and allow adegree of movement of the supported restoration similar to that of anatural tooth. Micro-spacers may also be included that define acontrolled gap between the well and the post. Preferably, themicro-spacers are flexible filled micro-spheres, micro-rods ormicro-balloons of uniform diameter.

The outer surface of the implant may include a plurality of ridges thatextend laterally, and a bottom portion that is tapered to produce aconical or ogival shape. The upper portion of the implant may have anenhanced diameter by flaring outwardly in the direction of the uppersurface of the implant, in a configuration similar to the head of a woodscrew.

The stump of the abutment may be angled in relation to the post and mayinclude one or more generally flat surfaces that oppose rotation of atooth restoration affixed to the stump.

The invention also relates to a computer-readable medium that carriesone or more sequences of instructions for digital imaging and design ofa dental implant system, and for providing instructions to a dentalCAD/CAM milling machine. In one embodiment, execution of the sequencesof instructions generates an analysis of surface and X-ray data providedby integration software that produces a digital model of a jaw of thepatient, and the development of contour data both for the implant andfor the abutment to suit a specific anatomy. Machine instructions arealso provided for milling the implant and the abutment from blocks ofthe millable ceramic. The software according to the invention enables arestoring dentist to produce implants and abutments of desired shapesand when needed, providing the dentist with total flexibility andminimizing the dentist's inventory. Moreover, the invention may beembodied as an implant system that includes an implant placed atextraction, also identified as an “immediate implant.”

An implant system according to the invention may also include a healingcap for covering the implant after placement of the implant in apatient. In one embodiment, the healing cap releases an antibioticcomposition.

Methods of use of a dental implant system are also disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and illustrateexemplary embodiments of the invention. It is to be understood that insome instances various aspects of the invention may be shown exaggeratedor enlarged to facilitate understanding.

FIG. 1 illustrates a first implant system in the prior art.

FIG. 2 illustrates a second implant system in the prior art.

FIG. 3 is a cross-sectional view of an implant system according to theinvention.

FIG. 4 is a perspective view of the implant of FIG. 3.

FIG. 5A is a detail view of an alternate configuration of the implantsystem of FIG. 3, while FIG. 5B illustrates the implant of FIG. 3coupled with a healing cap.

FIGS. 6A-6C illustrate a variant of the embodiment of FIG. 3, in whichopposing surfaces of the implant and of the abutment collar are curved.In particular, FIG. 6A illustrates an implant according to this variantbefore placement, and FIGS. 6B and 6C illustrate the implant systemafter placement and supporting a front tooth.

FIG. 7 illustrates an implant system according to invention afterimplantation into a patient's oral cavity.

FIGS. 8A-8B are respectively perspective and elevational views of avariant of the abutment of FIG. 3 having an angled stump, a collar withvariable thickness and perimeter, and a flat face.

FIG. 9 is a perspective view of another implant system according to theinvention.

FIG. 10 is a cross-sectional view of the implant system of FIG. 9.

FIG. 11 is a detail view of recesses in the well in a variant of theimplant of FIG. 9.

FIG. 12 is a cross-sectional view of a variant of the implant system ofFIG. 10, which has a flaring collar and a different arrangement of thegrooves in the abutment post and of the recesses in the implant well.

FIG. 13 is detail view of the coupling area between the implant well andthe abutment post, in which a retentive elastomeric product containingmicro-bubbles and micro-spacers is applied.

FIG. 14 is a schematic representation of a method of manufacturing adental system according to the invention, which includes advanced dataintegration and computer design of the implant, abutment, dentalrestoration and instructions to CAD/CAM machine.

FIG. 15 is a schematic representation of a method of manufacturing adental system according to the invention, which includes manual datainput and computer rendition of the implant, abutment and instructionsto CAD/CAM machine.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Detailed descriptions of embodiments of the invention are providedherein. It is to be understood, however, that the present invention maybe embodied in various forms. Therefore, the specific details disclosedherein are not to be interpreted as limiting, but rather as arepresentative basis for teaching one skilled in the art how to employthe present invention in virtually any detailed system, structure, ormanner.

Referring first to FIG. 3, an implant system according to the principlesof the invention includes an implant 20 and an abutment 22. Both implant20 and abutment 22 are made from a millable ceramic such as zirconia.“Made from a millable ceramic” is meant to describe a product made froma pure form of the millable ceramic (for example, from pure zirconia) orfrom a composition containing the millable ceramic. For the sake ofbrevity, the embodiments described hereinafter will be disclosed usingzirconia as the millable ceramic. Zirconia implant systems offer anumber of advantages over traditional titanium implant systems, aspreviously explained and as further explained in greater detailhereinbelow.

Implant 20 has a cylindrical shape with an outer surface 24 and an innersurface, which extends longitudinally inside implant 20 to define aninwardly tapered well 26 having, in this embodiment, the shape of atruncated cone. In other embodiments, the well may have differentshapes. Outer surface 24 and well 26 are connected by an upper surface28, which has an annular shape.

Outer surface 24 may be smooth or porous and have a plurality of ridges30 extending outwardly. The plurality of ridges 30 increase the area ofintegration between implant 20 and the surrounding bone. When implant 20is to be screwed in an opening drilled in the jaw of the patient, asingle ridge 30 may be disposed spirally around outer surface 24, asshown in FIG. 4, in a pattern comparable to the thread of a screw. Thesesurface patterns of outer surface 24 are known to a person skilled inthe art and will not be discussed in additional detail herein.

Still referring to FIG. 3, abutment 22 includes a stump 32, whichextends upwardly from implant 20 and is designed to support a dentalrestoration (for example, an artificial crown 34). Abutment 22 alsoincludes a post 36, which extends downwardly into well 26 and is shapedto mirror well 26. Preferably, post 36 and well 26 are shaped such that,when post 36 engages well 26, a gap or interstice is defined betweenpost 36 and well 26 for placement of a dental cement or of a flexibleproduct that provides not only a mechanical lock, but alsoshock-absorbing properties as explained in greater detail hereinafter.Such gap or interstice may be of even thickness, or may be of eventhickness between the lateral walls of post 36 and well 26 and bethicker between the bases of post 36 and well 26. While both well 26 andpost 36 are illustrated as having the shapes of truncated cones, butwell 26 and post 36 may also have a variety of other matching shapes.

A collar 38 is provided between stump 32 and post 36 and may be shapedwith different contours, for example, like a flange extending outwardlyof abutment 22. The perimetric extension of collar 38 at its base isequal to that of upper surface 28, such that, after coupling implant 20with abutment 22, the lower surface of collar 38 has a perimeter that isflush with the upper periphery of implant 20. The retentive productdisposed between post 36 and well 26 is also disposed between uppersurface 28 and the lower surface of collar 38. The combination of theflush joint and of the retentive product between upper surface 28 andcollar 28 eliminates or at least reduces the development of bacterialcolonies at the joint between implant 20 and abutment 22, and, when theretentive product has elastomeric properties, it provides ashock-absorbing effect to the supported restoration, resolving problemsaffecting implant systems in the prior art.

In addition, collar 38 provides a support base for artificial crown 34.Preferably, the bottom (also identified as margin in the trade) ofartificial crown 34 is shaped to match the upper surface of collar 38and be flush with the upper and lateral surface of collar 38, preventingor at least reducing the development of bacterial colonies between crown34 and abutment 22, and also facilitating a proper dental hygiene (forexample, flossing). Therefore, such a construction would provide a flushstructure that includes the margin of crown 34, the lateral surface ofcollar 38 of abutment 22, and upper outer surface 24 of implant 20.

In other embodiments of the invention, the collar may flare outwardly,for example, have an upper portion that is larger than the diameter ofthe implant, creating a longitudinally divergent profile like collar 44of FIGS. 5A and 116 of FIG. 12. The upper and lower surfaces of collar116 may be connected by a lateral circumferential wall that is eithercylindrical, conical or have a variety of other shapes.

The height (that is, the longitudinal extension) of collar 38 may alsovary and can be calculated by the restoring dentist based on thicknessmeasurements of bone and gum levels. The outer perimeter of the upperface of collar 38 may also be shaped as desired by the restoring dentistsuch to have a shape that matches the bottom or margin of the supportedrestoration while the lower face of the collar 38 has a same ordifferent face that matches upper surface of the implant, as shown inFIGS. 8A-8B.

In particular, FIGS. 8A-8B illustrate an abutment 74 having a collar 75,which has an upper face 77 that has a general shape to match thetransverse anatomic profile of a bicuspid tooth and a lower face 81 thathas a circular shape to match the upper surface of the implant whichsupports abutment 74. In addition, collar 75 has a longitudinal profilethat is wedge-shaped to adapt to the anatomy of the patient and thespecific positioning of the implant system. Such possible variations ofcollar 75 both in the horizontal and vertical directions illustrate animportant feature of the present invention, that collar 75 is infinitelymodifiable and is adaptable to the requirements of varying tissue heightand tooth size and shape. A person skilled in the art will appreciatethat infinitely modifiable collar 75 can have an upper face 77 mimickingthe transverse anatomic profile of any tooth or restoration as well as avarying height. As an example, tooth size adaptability allows the samesize implant to conform to a bicuspid sized tooth or to a molar toothwhile conserving the natural tooth anatomy of these very different sizedteeth. As another example, the infinitely modifiable collar allows forextreme adaptability in front teeth restoration, providing cosmeticresults heretofore unattainable. The infinitely modifiable collar can bedeveloped and produced with dental CAD/CAM equipment and the relatedsoftware, as explained in greater detail hereinbelow.

FIG. 5A illustrates a detail of a variant, in which upper surface 42 ofimplant 40 faces collar 44 of abutment 47 that has increased thicknessand that flares outwardly in comparison to collar 38 to conform to gumthickness of the patient and to achieve a best fit with the morphologyof the mouth and supported tooth. FIG. 5B illustrates instead implant 40coupled with a healing cap 46 after positioning in the alveolar bone, asdescribed in greater detail hereinafter.

FIGS. 6A-6C illustrate an embodiment of the invention, in which collar48 of abutment 49 and upper surface 50 of implant 52 have matingsurfaces that are not flat, but instead are contoured to adapt to aparticular configuration or location in the patient's mouth. Theillustrated example relates to an implant system for a front upper tooth64, where upper surface 50 of implant 52 and the lower surface of collar48 are contoured with a double curvature profile to adapt to the shapegenerated by the sum of the curvatures of the bone in the mesial-distaldirection and in the labio-lingual direction. The upper surface ofcollar 48 and the margin of crown 64 may also be contoured with a doublecurvature profile to adapt to the shape generated by the sum of thecurvatures of the gingiva in the mesial-distal direction and in thelabio-lingual direction. The healing cap may also be contoured (forexample, milled) to match upper surface 50 of implant 52.

Such custom contouring is facilitated by the availability of CAD-CAMequipment in the dentist's office, as explained in greater detailhereinafter. Data input to a CAD-CAM machine may be provided with avariety of tools, for example, with appropriate computer softwarereceiving input from the dentist.

Also as illustrated in FIGS. 6A-6C and 7, implant system 54 (supportingan artificial front tooth 64) and implant system 56 (supporting anartificial molar 66) can be implanted into a patient such that surfaces50 and 58 are at or near the surface of the bone (identified in FIGS. 6Band 7 respectively by reference numerals 60 and 62). The upper surfacesof collars 48 or 68 are also at or near the outer surface of thegingiva, indicated respectively by reference numerals 70 and 72.

Referring again to FIG. 3 and to FIGS. 8A-8B, stump 32 may have alongitudinal axis that is coincident with the longitudinal axis ofabutment 22, or may have a longitudinal axis that is angled in relationto the longitudinal axis of abutment 74, in the manner of stump 76 inFIGS. 8A and 8B. The use of an angled stump may be particularly usefulwhen the implant system supports an artificial tooth that is placed tohave an angled axis in relation to the implant, or when the implantsystem is disposed at an angled position with respect to the adjacentteeth.

One more advantage of an implant system according to the presentinvention is that the restoring dentist may determine the appropriatedirection for ideal placement of the implant in the bone withoutconsidering the angle of the abutment stump in relation to the abutmentpost (see, for example, stump 76 and post 79 in FIGS. 8A and 8B). Therestoring dentist can then mill an abutment 75 from a zirconia block toproduce a stump 76 having a desired angle by using a CAD-CAM systemadapted for a dental practice and driven by appropriate software, asdescribed hereinbelow. This arrangement provides the dentist with totalflexibility by virtually eliminating his inventory of pre-manufacturedimplants and abutments of different sizes and angles, and by enablinghim to manufacture each component of the implant system when needed, forexample, to even manufacture an implant at the time of placing theimplant into the bone, and an abutment at the time of joining theabutment to the implant, usually months later.

The stump of the abutment may include one or more faces that aregenerally flat. FIGS. 8A and 8B depict stump 76 having a single flatsurface 78, which, when matched with a corresponding flat face within adental restoration (for example, within an artificial crown) preventsthe rotation of the restoration in relation to post 79. This arrangementprovides for greater stability of the crown. In situations where stump76 is angled with respect to the longitudinal axis of post 79, therestoring dentist may rotate abutment 74 within the implant well toimprove minor angulations or tooth spacing, until the desired angularposition of stump 76 is achieved.

FIGS. 9 and 10 illustrate another embodiment of the invention. Like thepreviously described embodiments, implant system 80 includes an implant82 and an abutment 84. Implant 82 has a lower portion 86 that tapersinwardly toward the lower end of implant 82 to prevent an undesireddegree of penetration of implant 82 into the patient's bone or into aneighboring bodily cavity (for example, the paranasal sinus). Whenimplant 82 is employed, the alveolar bone of the patient may be drilledwith a tapered bit, such that main body 88 of implant 82 cannot movebeyond the end of the bored opening since such end has a smallerdiameter than main body 88.

Still referring to FIGS. 9 and 10, implant 82 and abutment 84 may beengaged one to the other with a retentive elastomeric material 90, whichis disposed in an interstice or gap 92 between implant 82 and abutment84. In particular, retentive elastomer 90 is disposed in the gap betweenwell 94 and post 96 and between collar 98 and upper surface 100.

Retentive elastomer 90 has resilient (or flexible) properties, suchthat, after the coupling of abutment 84 with implant 82, abutment 84retains a limited degree of mobility through compression and expansionof the resilient retentive elastomer. Retentive elastomer 90 may or maynot have adhesive properties. The described arrangement enables anartificial tooth supported by abutment 84 to move in a fashion similarto that of a natural tooth. This is an advantageous feature of theinvention, because implant systems of the prior art are rigid inrelation to the alveolar bone.

In one embodiment of the invention, the resilient retentive elastomer isa silicone or silicone-containing material and may be eithermono-component or bi-component, for example, may be an elastomericmaterial formed from two components (a base resin and a catalyst orcuring agent) mixed at the nozzle of a dispenser syringe at the time ofapplication. In another embodiment, the resilient product (for example,silicone) has a composition or includes additives that make it resistantto oral yeast.

Referring to FIG. 13, retentive elastomer 90 incorporates micro-bubbles101, which may be shaped like small cavities formed within retentiveelastomer 90 or like micro-balloons filled with an enduring gas such tofavor the above described movement of abutment 84 in relation to implant82. The enduring gas or the retentive elastomer should be such toprevent dispersion of the gas through retentive elastomer 90, preservingthe volume of micro-bubbles 101 over time.

One of the key functions of micro-bubbles 101 is to provide expansionand compressibility within interstice or gap 92. Retentive elastomer 90may also contain micro-spacer elements that controllably distance well94 from post 96. Such micro-spacer elements preferably have equaldiameters and may be shaped in various shapes, for example, like filledflexible micro-spheres 102 or like micro-rods. The micro-spacers aretypically uniform in diameter. The provision of a gap 92 filled withretentive elastomer 90 containing micro-bubbles 101 and micro-spacerelements 102, which insures a controlled spacing between implant 82 andabutment 84 and which allows a relative movement between implant 82 andpost 84, is another relevant aspect of the present invention.

Retentive elastomer 90 acts as a stress-relieving joint, for example,when the supported restoration is subject to compressive movementsduring chewing.

Referring again to FIG. 10, one or more grooves 104 may be carved onpost 96 transversally to the longitudinal axis of abutment 84. Grooves104 create one or more annular cavities between post 96 and well 94,which are filled with a retentive product (in one embodiment, withretentive elastomer 90) and increase resistance to extraction of post 96from well 94 when a tensile strength is applied to abutment 84. In oneembodiment, one or more parallel horizontal grooves 104 are provided; inanother embodiment, a single spiral groove is provided.

Still referring to FIG. 10, the joining effect between post 96 and well94 is further increased by providing one or more recesses 106 in well94, which may or may not be disposed in facing relationship with grooves104 to jointly create an annular cavity of toroidal shape around post96. Recesses 106 may be in equal number as grooves 104, or not all ofgrooves 104 may have a facing recess 106. For example, the lowest grooveon post 96 may not have a facing recess, in order to avoid the use ofexcessive force if the dentist desires to disengage abutment 84 fromimplant 82, for example, if abutment 84 needs to be replaced orrepaired.

Preferably, recesses 106 are shallow, to facilitate extraction ofabutment 84 from well 94. In the embodiment depicted in FIG. 11,recesses 107 are shaped like notches on well 109.

A person skilled in the art will appreciate that grooves 104 andrecesses 106 may be provided in a variety of shapes, patterns andnumbers, in facing or non-facing relationships, and that, in differentembodiments, only grooves 104 may be provided, or only recesses 106, ora combination of both. Moreover, the surfaces of post 96, well 94, uppersurface 100 or collar 98 may be treated to increase adhesion and sealingeffect, for example, may be etched or sandblasted.

For example, FIG. 12 illustrates another embodiment of the invention, inwhich abutment 108 includes upper and lower grooves 111 and 113 infacing relationship respectively with upper and lower recesses 115 and117 on well 112 of implant 114, and central groove 110 that has nocorresponding recess. Implant system 100 also includes a collar 116 onabutment 108 that flares upwardly and outwardly, as describedhereinabove.

Referring again to FIG. 10, one or more longitudinal grooves 118 may becarved on post 96, which are particularly effective in countering anyrotational forces applied on abutment 84. In one embodiment, twolongitudinal grooves 118 are defined on post 96 in symmetricalpositions. In other embodiments, longitudinal recesses (not shown) maybe defined in well 94 instead of longitudinal grooves 118, or bothlongitudinal grooves 118 and longitudinal recesses may be provided,either in facing relationship or offset one with respect to the other.The anti-rotational effect of longitudinal grooves 118 is particularlyimportant for implant systems supporting artificial front teeth. Thelongitudinal recesses in well 94 may also be used by the restoringdentist to place the implant in the bone by using a placement tool thathas protrusions configured to fit in the recesses on the well, such tograb and rotate implant 82. In this situation, the longitudinal recesseswill preferably be semi-cylindrical or have other shapes that are bestsuited to engage the placement tool. It should be understood in that indifferent embodiments of the invention only one or more lateral grooveson the abutment post or recesses on the well may be provided, or onlyone or more longitudinal grooves on the post or recesses on the well, orboth.

When retentive elastomer 90 is employed, the presence of grooves 104and/or recesses 106 creates a sealing ring effect, similar to the effectprovided by an O-ring, which creates a mechanical lock between implant82 and abutment 84. The strength provided by such mechanical lock issuch that retentive elastomer 90 may have no chemical orphysico-chemical adhesive properties, so that the joint strength may beof purely mechanical nature. It will be within the judgment of therestoring dentist to assess whether retentive elastomer 90 should alsohave adhesive properties.

Still referring to FIG. 10, implant 82 and abutment 84 may bemanufactured in a dentist's office using a dental CAD-CAM machinecontrolled by appropriate software. Zirconia blocks suitable for millingmay be supplied in a partially sintered or crystallized state and, aftermilling the zirconia is baked in a special high heat oven to achieve thedesired strength. The blocks emerge from the oven sterile, clean, with agood implant surface for bone integration, and ready to be placed.

The zirconia blocks are custom shaped using a CAD-CAM machine in thedentist's office or at an external laboratory. Data input to the CAD-CAMmachine is provided via computer instructions.

In a first step of an embodiment of the invention, an advanced system ofintegration software allows the restoring dentist to design anartificial tooth system on a digital model of the patient by integratingsurface data with X-ray data. One producer of such integration softwareand related X-ray equipment is Sirona Dental Systems, Inc. of Salzburg,Austria and Long Island City, N.Y.

In a second step, using software according to the invention, a computerprocessor analyzes the surface data and the X-ray data produced in thefirst step and, based on the anatomy of the mouth of the patient and theconfiguration of the bone where the implant is to be placed, an implantand an abutment with the desired properties are developed. Suchproperties include length and diameter of the implant, depth of theimplant well, length and taper of the abutment post, numbers andpositions of grooves and recesses (if any) on the abutment post and theimplant well, diameter, dimensions and shape of the upper surface of theimplant (for example, whether flat or curved), height and shape of theabutment collar, height, angle and taper of the stump, and number andposition of any flat surfaces on the stump. Therefore, softwareaccording to the second step enables the production of a digitallyimaged and designed implant system that is customized according to theanatomy and wishes of the patient, and to the judgment of the restoringdentist. Moreover, the implant system may be modified digitally asdesired.

The developed data are then used to provide CAD/CAM data for a dentalmilling machine, which manufactures an implant and an abutment havingthe desired characteristics, in a dental office or in an outsidelaboratory. Using the above described digitized images and designs andsuitable CAD/CAM equipment, the implant and/or the abutment can beproduced when needed, at different times if desired, providing thedentist with total flexibility and significantly reduced inventories.The main features of software according to the present embodiment aresummarized in FIG. 14.

In another embodiment of the invention, standard input data to theCAD/CAM machine may be provided with different tools and/or methodsinstead of using the above described integration software, in a mannersimilar to the tools and methods presently employed to produce dentalrestorations such as crowns. For example, the restoring dentist mayinput data at a keyboard or at a screen, filling in choice boxes relatedto parameters of the implant system such as abutment angle and collarheight according to the process summarized in FIG. 15. The input dataused by the dentist may be generated from 2-dimensional X-rays, dentalcameras, or through direct measurements. Software according to thepresent invention then provides a three-dimensional image of the implantsystem and enables the dentist to adjust parameters (for example, thediameter and length of the abutment post) according to his/herprofessional judgment.

An important feature of the present invention is the ability to generatecomplementary designs of implant, abutment and supported restoration(for example, of an artificial crown) within narrow tolerance ranges.Starting from X-ray data, the restoring dentist can both develop, andmachine in his office to tight tolerances, the implant, the abutment andalso the crown, insuring not only a proper anatomical fit of the implantsystem and restoration within the mouth of the patient, but also a fitamong the components of the implant system and restoration within narrowtolerances.

In addition, use of 3D X-ray imaging with the appropriate accuracyenables the design of a root-form implant that can be milled from X-raydata in advance, before a tooth is extracted, and that can be ready forplacement after extraction. When placed at extraction, an implant istermed an “immediate implant.” The implant, abutment and restoration canalso be prepared in advance, and then the implant, abutment and crownare joined one to the other and immediately placed after the tooth isextracted, or are joined one to the other in situ. Joining may beperformed using a dental cement, or the implant may be joined to theabutment by providing grooves and/or recesses on the abutment postand/or the implant well and then filling the gap between abutment postand implant well using a retentive elastomeric product as describedhereinabove. Alternatively, implant and abutment may be designed andmilled as a single piece rather than as two separate pieces.

Alternatively, a tooth may be extracted and the restoring dentist mayscan the remaining tooth socket with a dental camera or scan theextracted tooth or an impression of the socket. An implant ofappropriate shape is then developed and milled, with a shape that is notcylindrical, but that has a profile matching the shape of the toothroot. The implant may also have an upper surface that is appropriatelycontoured for best fit with the bone, and the abutment would then have acollar with a lower surface that is appropriately contoured to engagethe upper surface of the implant. The implant can be placed in thesocket either on the same day as the extraction, or, if not possible, onthe following day after cleaning the socket from blood clots that mayhave formed. As mentioned, implant and abutment may be manufactured asseparate pieces or as a single piece and subsequently placed.

In a method of use of a dental implant system according to theinvention, a restoring dentist initially drills an opening in the boneof the patient that has a diameter suited for the insertion of animplant, as it is known in the art. The opening may be drilled with abeveled bit, in order to have a tapered end of the opening, or with astraight outer wall for a sinus lift procedure.

When it is desired to avoid a penetration of the implant into the bonebeyond a certain depth (for example, when a bone of limited thicknessdivides the mouth from a bodily cavity such as the paranasal sinus), animplant such as implant 82 of FIGS. 9 and 10 is used. Lower portion 86of implant 82 will then be received in the tapered end of the opening.

Implant 82 is joined to the surrounding bone according to a method knownin the art. In particular, implant 82 may be provided with a spiral,screw-like thread on its outer surface and be screwed into the opening,or may be simply passively placed in the bone for integration over aperiod of time. In that case, the restoring dentist covers well 94 witha cover or healing cap and stitches the surrounding gum tissue over oraround the healing cap, or reduces the cap and sutures over it.

In one embodiment, the cover or healing cap includes a stem portion thatis inserted within well 94, and a hemispherical or cylindrical capportion configured to rest on the upper surface 100, covering well 94.Before inserting the cover or healing cap, the restoring dentist mayapply an antibiotic product within well 94. In addition, the cover orhealing cap may be constructed to elute a desired product (e.g. anantibiotic) over time.

The healing cap may be specially contoured to snap into well 94. Forexample, the healing cap may include semi-cylindrical longitudinalprotrusions that engage semi-cylindrical longitudinal recesses in well94, and may be provided in standard sizes or be specially machined tothe desired shape.

Implant 82 is prepared before the implant procedure by using a CAD-CAMsystem and software as described hereinabove. Abutment 84 can also beprepared ahead of time using software as described hereinabove, and bothimplant 82 and abutment 84 may include constructive features (such ashorizontal and vertical grooves in the well and on the post) as desiredby the restoring dentist, as well as ridges on the outer surface of theimplant.

Implant 82 is placed first, covered with a healing cap, and afterintegration and healing, implant 82 is uncovered and the healing cap isremoved. A retentive elastomer product or a dental cement is appliedwithin the well, in sufficient quantity to insure a proper filling ofgap 92, including any horizontal or vertical grooves that may be presentand also including the interstice between collar 98 and upper surface100. Preferably, the restoring dentist applies a resilient retentiveelastomer that contains micro-bubbles as well as micro-spacers of equaldiameter to enable a relative movement of abutment 84 in relation toimplant 82 and to insure a uniform thickness of gap 92. For example, therestoring dentist may inject a bi-component, Candida-resistant siliconeretentive elastomer containing both micro-bubbles and flexiblemicro-spacers using a double-barreled syringe, in which two resincomponents (a base product and a catalyst or curing agent) become mixedat the nozzle.

Finally, the artificial tooth or bridge is affixed to the abutment.

The present invention also enables a restoring dentist to prepare animplant, abutment and restoration (for example, a crown) in the dentaloffice by using CAD/CAM equipment programmed by using 3-dimensionalX-ray data of the patient, as described hereinabove. Implant, abutmentand crown may be placed during a single session and movement of thecrown before osseo-integration of implant 82 may be prevented bystabilizing the crown in place bonding it to the adjacent teeth with adental cementing agent (known in the trade as a luting agent).

In particular, an immediate implant system can be created, shaped totight tolerances to match the socket of an extracted tooth by scanningthe tooth or tooth socket or an impression of the tooth socket afterextraction, or by using 3-dimensional images of the tooth structurebefore extraction. In that scenario, the restoring dentist will shapethe implant system (particularly the outer and upper surfaces of theimplant) to reflect socket or tooth root configuration, and implantpassively an implant shaped to have a divergent profile that closelyresembles the socket or the root area of the extracted tooth.

The preceding description has illustrated a number of advantages of animplant system according to the present invention, some of whichinclude:

1. A healthy emergent profile of the implant system and of the crowncarried by the implant system.

2. A stress-relieving joint when implant and abutment are joined with aretentive elastomeric product, which acts as a shock absorber.

3. Customization through a CAD-CAM system, which allows an essentiallyperfect tailoring of the implant system to patient anatomy, and whichenables an inventory reduction of finished product on an as neededbasis.

4. Non-toxicity due to the use of zirconia or other bio-compatibleceramic material.

5. No electro-negativity due to the use of ceramic products.

6. No screws or joints that leak, harbor bacteria or break.

7. The entire implant system (implant and abutment) can be colored whiteor off-white for best cosmetic results. This makes the implant systemless noticeable when placed in a thin bone or front mouth area.

8. In-office milling allows for design flexibility, greatly increasingthe usefulness of the implant and implant system per se, and thecreativity of the restoring dentist.

9. The entire implant system, which supports the dental restoration, canbe milled from the same ceramic product, customizing size and shape ofthe implant, and the abutment can be designed for the needed height,angle of divergence and diameter.

10. A tooth form implant, abutment and restoration can be milled at thesame time, even before a tooth is extracted, and can be shaped to matchthe tooth socket.

11. The abutment can be attached to the implant with an interstitialretentive elastomer that maintains an even gap thickness. Thisthickness, in turn, allows a degree of movement of the artificial tooth.

While the invention has been described in connection with the abovedescribed embodiments, it is not intended to limit the scope of theinvention to the particular forms set forth, but on the contrary, it isintended to cover such alternatives, modifications, and equivalents asmay be included within the scope of the invention. Further, the scope ofthe present invention fully encompasses other embodiments that maybecome obvious to those skilled in the art and the scope of the presentinvention is limited only by the appended claims.

1. A method of manufacturing and delivering a dental implant system, themethod comprising: providing an implant system comprising, an implanthaving an outer surface, an inner surface, and an upper surfaceannularly connecting the outer surface to the inner surface, the innersurface defining a well projecting from the upper surface into theimplant, the implant being monolithic and made from a millable ceramic;and an abutment having a post, a stump, and a collar, the post having ashape configured to engage the well while leaving a gap therebetween,the stump being configured to support a dental restoration, the collarextending outwardly from the abutment at a transition between the postand the stump and having a lower outer perimeter substantially equal toan outer perimeter of the upper surface of the implant, the abutmentbeing made from the millable ceramic, wherein at least one of, one ormore grooves are defined in a wall of the post of the abutment, or oneor more recesses are defined in a wall of the well of the implant;disposing a retentive product over the post or the well, such to fillthe gap and one or more of the one or more grooves or one or morerecesses; and coupling the post of the abutment with the well, theretentive product being selected to provide at least a mechanical lockbetween the implant and the abutment retaining the abutment in the wellafter placement by a dentist while allowing abutment removal by thedentist if necessary.
 2. The method of claim 1, wherein disposing aretentive product comprises disposing a product comprisingyeast-resistant silicone.
 3. The method of claim 1, wherein disposing aretentive product comprises disposing a retentive elastomeric product.4. The method of claim 3, wherein disposing a retentive productcomprises disposing a retentive elastomeric product containing spacers,such as to provide a controlled distance between the well and the post.5. The method of claim 4, wherein the spacers are of substantially equaldiameter.
 6. The method of claim 1, further comprising the step ofproviding a computer-readable medium carrying one or more sequences ofinstructions for manufacturing a dental implant system, whereinexecution of the one or more sequences of instructions by one or moreprocessors causes the one or more processors to perform the steps of:analyzing surface and X-ray data to produce a three-dimensional model ofa jaw and a tooth of a patient; developing contour data of the implantand of the abutment suited for an anatomy of the patient; and producingmachine instructions for milling the implant and the abutment fromblocks of the millable ceramic.
 7. The method of claim 1, whereinproviding the implant system comprises providing the collar shaped tohave an upper outer perimeter configured to match a transverseanatomical profile of a natural tooth.
 8. The method of claim 7, furthercomprising the step of determining the upper outer perimeter of thecollar from X-ray data.
 9. The method of claim 1, wherein providing theimplant system comprises providing the outer perimeter of the uppersurface of the implant shaped to conform to a surrounding bony ridge ofa jaw at the dentist's discretion and the collar with a heightdetermined at the dentist's discretion to find optimal position inrelation to gingival crest to improve cosmetic appearance.
 10. Themethod of claim 1, wherein providing the implant system comprisesproviding the collar with a variable height.
 11. The method of claim 1,wherein providing the implant system comprises providing at least oneof, the upper surface of the implant and a bottom surface of the collar,or an upper surface of the collar and a margin of a dental restoration,shaped with matching curved surfaces.
 12. The method of claim 1, whereinproviding the implant system comprises providing the collar with aflaring lateral surface.
 13. The method of claim 1, wherein providingthe implant system comprises producing the implant and the abutment withthe millable ceramic having a white or off-white color to achieve adesired cosmetic result.
 14. The method of claim 3, wherein disposing aretentive elastomeric product comprises disposing a retentiveelastomeric product containing micro-bubbles such to provide elasticityand compressibility within the gap.
 15. The method of claim 1, whereinproviding the implant system comprises providing a plurality of groovesin the wall of the post and a plurality of recesses in the wall of thewell, and wherein a lowest groove in the wall of the post has no facingrecess, such to decrease an amount of force required by the dentist toextract the post from the well.